[Risk Factors for Recurrence in Patients with Pathological Lymph Node-Positive Prostate Cancer after Extended Lymph Node Dissection in Laparoscopic and Robotic-Assisted Radical Prostatectomy].

From April 2007 to April 2018, we performed lymph node dissection in 305 cases of laparoscopic radical prostatectomy and 202 cases of robot-assisted radical prostatectomy at our hospital, and there were 68 cases with positive lymph node metastasis (pN1). Of these 68 cases, we examined retrospectively 62 cases in which extended lymph node dissection (ELND) was performed. The median number of removed lymph nodes was 25 (interquartile range [IQR] ; 18-34) and the median number of metastatic lymph nodes was 1 (IQR ; 1-3). Postoperative prostate-specific antigen (PSA) recurrence was observed in 40 of the 62 patients. The median time to PSA recurrence was 24 months. After univariate analysis, PSA at initial diagnosis (iPSA) of 10 ng/ml or more, pathological Gleason score (pGS) of 8 or more, total number of lymph node metastases of 2 or more, and positive surgical margin (RM＋) were found to be riskfactors of PSA recurrence. In multivariate analysis, iPSA of 10 ng/ml or more, pGS of 8 or more and RM＋ were independent riskfactors of PSA recurrence (p＜0.05). In the cases without riskfactors such as iPSA≥10, pGS≥8, and RM＋, immediate postoperative adjuvant therapy may be avoided even with pN1.